Cooling Apparatus for Optical Engine Assembly

ABSTRACT

The present invention sucks in the air from the fan at the top of the imaging assembly of the optical engine and blows the air from the air duct device downward. Some of the air is guided by the diversion board, aslant guiding surface, and aslant isolating board of the air duct device and blown into the imaging assembly for cooling the optical components. Some of the air is guided through a first air duct, a second air duct, and a third air duct extended from the outside of this main body respectively to the outer surface of the light valves for heat dissipation. Further, some of the airflow is guided into a branch air duct and blown to a vent of the imaging assembly of the optical engine. By means of the changing direction diversion board, the airflow is guided towards the plarizer module such that the heat at the projection lens of the plarizer module can fully be dissipated, and flown out from a vent on the other side. It produces a lateral airflow, and interferes with the vertical airflow blown directly downward from the fan into the interior of the housing for increasing the heat dissipation efficiency, reducing the volumes of fans and the cost.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an optical engine of projector,and more particularly, to a cooling apparatus for optical engineassembly.

[0003] 2. Description of the Prior Art

[0004] As the optical-electronic technology develops in a fast phase,the general projecting display device usually uses the high power bulbas the light source to project a clearer image with high brightness.However, the high power bulb also produces high temperature at the sametime. Therefore, a fan is used for cooling such prior-art projectingdisplay device to avoid the rise in temperature and the deterioration ofoptical components due to the light incidence of the bulb. Although thefan is used for the heat dissipation, it also generates noises.Therefore, the improvement of heat dissipation with a limited fanbecomes an important research and development topic for the industry.

[0005] Please refer to FIG. 1, which shows an imaging assembly 10 of anoptical engine of a prior-art display device, and a projecting lamp (notshown in the figure) is installed under the imaging assembly 10. Thewhite beam emitted from the projecting lamp as shown in FIG. 2 isdivided into three colors: red, blue, and green by a X-plate 12 insidethe housing 11 of the image assembly 10, and each colored light isguided into three plarizer modules 13, 14, 15 each comprised of aplarizer and a half wave plate, and modulated by three sets ofmodulating units comprised of three light valves 161, 162, 163, andsynthesized by a X-cube 17, and finally projected onto a screen from aprojection lens (not shown in the figure) disposed at the front end ofthe X-cube 17.

[0006] The high intensity light projected by the foregoing high-powerlight bulb passes through the optical components such as the X-plate 12,three plarizer modules 13, 14, 15, three light valves 161, 162, 163 andthe X-cube 17, and will produce heat of high temperature. Heatdissipation must be performed, so that the temperature will not exceedthe suitable operating temperature range, or else affecting theproperties of the optical components and deteriorating the color andoptical evenness of the image as well as lowering the quality ofprojection, or even damaging the expensive optical components in someserious cases. Although the high intensity light emitted by theforegoing high-power projecting lamp will heat up the temperature ofeach optical component along the optical path, this invention onlyintends to solve the heat dissipation problem of the optical componentsin the reflecting LCD image assembly 10, and the description of the heatdissipation of the related prior-art imaging assembly 10 will be givenbelow.

[0007] The three light valves 161, 162, 163 of the aforementionedprior-art assembly 10 are respectively fixed onto the front and bothsides of the housing 11, and two through holes 111, 112 with aslantsurface are disposed in the front section of the housing 11, and fans181, 182 is respectively mounted onto each hole such that the fans 181,182 are disposed between the three light valves 161, 162, 163 forsucking the air from the outside. The air is blown to the relatedoptical components between the three sets of modulating units, and thedirection of airflow is shown by the arrows in FIG. 2. The air flowdissipates the heat produced by the X-plate 12, the polarizer modules13, 14, 15, the light valves 161, 162, 163 and the X-cube 17 in thehousing 11. However, since the top of the housing 11 is sealed and onlythe bottom has openings, and the three light valves 161, 162, 163 arefixed onto the side of the housing 11, the air is blown through thethree sets of modulating units. Most of the air from the fans 181, 182through the three sets of modulating units can only be blown to theoptical components such as the X-plate 12, the plarizer modules 13, 15on both sides, and the X-cube 17. It is difficult for the air to beblown into the corners of the plarizer module 14 for a through heatdissipation. In the meantime, only a small portion of the bouncing airis blown to the surfaces of the three light valves 161, 162, 163 and theair is unable to blow onto the external surface of the housing 11. Itthus causes the uneven airflow in the housing 11, and makes the lightvalves 161, 162, 163 and the polarizer module 14 unable to effectivelydissipate the heat which affects the functions of the optical componentsor even deteriorates the optical components due to the high temperature.In addition, the two fans 181, 182 used in the imaging assembly 10, alsoincreases the noise, that lowers the quality of the entire projectingdisplay device.

SUMMARY OF THE INVENTION

[0008] The objective of this invention is to provide a cooling apparatusfor optical engine assembly that evenly distributes the airflow insideand outside the imaging assembly to enhance the heat dissipationefficiency of the optical components and extend the life of the opticalcomponents.

[0009] Another objective of this invention is to provide a coolingapparatus for optical engine assembly that comes with a fan toeffectively use the heat dissipation efficiency of the airflow to reducethe use of fans, lower the cost, noise, and complexity of circuitcontrol.

[0010] Another further objective of this invention is to provide acooling apparatus for optical engine assembly that uses a changingdirection diversion board to interfere the horizontal airflow and thevertical airflow in order to enhance the heat dissipation effect.

[0011] To achieve the above objectives, the present invention sucks inthe air from the fan at the top of the imaging assembly of the opticalengine and blows the air from the air duct device downward. Some of theair is guided by the diversion board, aslant guiding surface, and aslantisolating board of the air duct device and blown into the imagingassembly for cooling the optical components. Some of the air is guidedthrough a first air duct, a second air duct, and a third air ductextended from the outside of this main body respectively to the outersurface of the light valves for heat dissipation. Further, some of theairflow is guided into a branch air duct and blown to a vent of theimaging assembly of the optical engine. By means of the changingdirection diversion board, the airflow is guided towards the plarizermodule such that the heat at the projection lens of the plarizer modulecan fully be dissipated, and flown out from a vent on the other side. Itproduces a lateral airflow, and interferes with the vertical airflowblown directly downward from the fan into the interior of the housing.

[0012] To make it easier for our examiner to understand the objective ofthe invention, its structure, innovative features, and performance, weuse a preferred embodiment together with the attached drawings for thedetailed description of the invention.

BRIEF DESCRIPTION OF DRAWINGS

[0013] Other features and advantages of the present invention willbecome apparent in the following detailed description of the preferredembodiments with reference to the accompanying drawings, in which:

[0014]FIG. 1 is a perspective view of an imaging assembly of a prior artoptical engine.

[0015]FIG. 2 is a cross-sectional diagram of an imaging assembly of aprior art optical engine.

[0016]FIG. 3 is a cross-sectional diagram of an imaging assembly of anoptical engine according to the present invention.

[0017]FIG. 4 is a structural diagram of the air duct device according tothe present invention.

[0018]FIG. 5 is a perspective view of the heat dissipation device of animaging assembly of the optical engine according to the presentinvention.

DETAILED DESCRIPTION

[0019] In the detailed description of the preferred embodiments, itshould be noted that like elements are indicated by the same referencenumerals throughout the disclosure.

[0020] Please refer to FIG. 3 for a preferred embodiment of the presentinvention, comprising an imaging assembly 20, wherein two vents 202, 203are disposed at an aslant surface of a housing 201. A light source (notshown in the figure) is installed below the imaging assembly 20. Thebeam emitted from the light sources passes through the X-plate 22 insidethe imaging assembly 20.

[0021] The white beam is divided into three colors: red, blue, and greenby a X-plate 22 and each colored light is guided into three plarizermodules 23, 24, 25 each comprised of a plarizer and a half wave plate,and modulated by three sets of modulating units comprised of three lightvalves 261, 262, 263, and synthesize by a X-cube 27, and finallyprojected onto a screen from a projection lens (not shown in the figure)disposed at the front end of the X-cube 27. Further, the dotted linerepresents the relative position on which an air duct device 30 of apreferred embodiment of the present invention is covered on the housing201, and a changing direction diversion board 28 is disposed on a sideof the plarizer module 24.

[0022] In FIG. 4, a main body 31 of the air duct device 30 is isolatedby a partition 311 into a front air duct 312 and a rear air duct 313. Afirst air duct 3131 is formed on one side of the main body 31 of therear air duct 313. The first air duct is extended from the outside ofthe main body 31, and form a downwardly opened opening. In addition, abolt hole 3132, 3133 is disposed on each side of the main body 31 at therear air duct 313, and the bolt hole 3132 is disposed on the downwardlyaslant guiding surface 3134. A positioning hole 3135 and a positioninglatch 3136 are disposed respectively on two corners of the main body 31,and a branch air duct 3137 extended downward and disposed under thecorner of the main body 31 where the positioning latch 3136 is located.An outlet at the inner side of the guiding direction is formed at theend of the branch air duct 3137 by a guiding board 3138.

[0023] Furthermore, the front air duct 312 of the air duct device 30 islocated at its center, and divided into a right air duct 3122 and a leftair duct 3123; an aslant isolating boards 3124, 3125 is disposed in theright air duct 3122 and a left air duct 3123. The aslant isolating board3124, 3125 is respectively disposed in the direction opposite to the twoaslant surface of the diversion isolating board 3121 between the rightair duct 3122 and the left air duct 3123. The right air duct 3122 andthe left air duct 3123 are then divided into two again, such that theright air duct 3122 and the left air duct 3123 at the sides of the mainbody 31 respectively form a second air duct 3126 and a third air duct3127 and extend respectively to the outer side of the main body 31 ofthe air duct, and their outlets form a downwardly opened outlet. A bolthole 3128 is disposed at the center of the guiding isolating board 3121.The above arrangement constitutes an air duct device 30 for dissipatingheat.

[0024] In FIG. 5, the air duct device 30 of this invention is disposedon the housing 201 of the imaging assembly 20 of the optical engine. Bymeans of the bolt holes 3132, 3133, 3128 of the air duct device 30, theair duct device 30 is fixed onto the housing 201, such that the outletsincluding the first air duct 3131, the second air duct 3126, and thethird air duct 3127 of the air duct device 30 respectively lead to theexternal surfaces of the light values 261, 262, 263.

[0025] Furthermore, the outlet of branch air duct 3137 of the air ductdevice 30 is guided to a vent 202 on the aslant surface of the housing201 of the imaging assembly 20. In addition, a fan 40 is disposed at theupper side of the main body 31 of the air duct device 30 to cooperatewith the positioning latch 3136 and the positioning hole 3135 to fix thefan to the air duct device 30.

[0026] When the heat dissipation device of the imaging assemblyaccording to a preferred embodiment of the present invention performsthe cooling operation, the fan 40 at the upper section sucks in the airat the upper section, and blows the air downward from the air ductdevice 30. By means of the guidance of the guiding isolating board 3121,aslant guiding surface 3134, and aslant guiding board 3124, 3125, someof the airflow is blown inside the imaging assembly 20 for cooling theoptical components including the X-plate 22, the plarizer modules 23,24, 25 and the X-cube 27 and the inner surface of the light valves 261,262, 263. Some of the air is guided through a first air duct 3131, asecond air duct 3126, and a third air duct 3127 extended towards theexternal side of the main body 31. The outlets of the first air duct3131, the second air duct 3126 and the third air duct 3127 s are ledrespectively to the external surfaces of the light valves 261, 262, 263for performing the heat dissipation.

[0027] Further, some of the air is guided into the branch air duct 3137extended towards the external side of the main body 31 and led to a vent202, and then blown towards the vent 202 via the guiding board 3138. Bymeans of the guidance of the changing direction diversion board 28, theairflow is guided to blow towards the e plarizer module 24, so that theairflow passes through the plarizer module 24 between the lenses andallows the lens of plarizer module 24 to be cooled thoroughly, and thenbe flown out from a vent 203 on the other side. It produces a lateralairflow, and interferes with the vertical airflow blown directlydownward from the fan 40 into the interior of the housing 201 and thusenhancing the heat dissipation effect. By the above air duct device 30and the changing direction diversion board 28, an even smooth flow isformed inside the imaging assembly 20 to evenly allocate the cool aireffectively use a single fan 40 to blow out the airflow, reduce thenumber of fans used, and lower the cost, noise, and complexity of thecircuit control.

[0028] Similarly, the reflection LCD light valve system used as anexample for the description of a preferred embodiment of this inventioncan be applied to the optical system having similar structures such asthe light valve of a digital micro-mirror device or the penetrative LCDlight valve.

[0029] While the invention has been described by way of example and interms of a preferred embodiment, it is to be understood that theinvention is not limited thereto. To the contrary, it is intended tocover various modifications and similar arrangements and procedures, andthe scope of the appended claims therefore should be accorded thebroadest interpretation so as to encompass all such modifications andsimilar arrangements and procedures.

1. A cooling apparatus for optical engine assembly, comprising: animaging assembly, having an interior section and a housing, the interiorhaving a changing direction diversion board; at least a light valvedisposed on one side of the housing; a air duct device, covered onto thehousing, wherein at least one isolating board forming a plurality of airducts, and such air ducts respectively leading to the interior of theimaging assembly, extending from an external side to an external surfaceof the light valve and the changing direction diversion board; and afan, fixed above the air duct device.
 2. The cooling apparatus foroptical engine assembly of claim 1, wherein the imaging assembly at itsinterior comprises at least one set of plarizer module, and the changingdirection diversion board is disposed on one side of the plarizermodule.
 3. The cooling apparatus for optical engine assembly of claim 2,wherein the housing of the imaging assembly comprises at least one vent,a branch air duct extending from the external side of the housing of theimaging assembly towards to a vent, and guiding the airflow from the endof the outlet of the guiding board to the vent, and facing at thechanging direction diversion board.
 4. The cooling apparatus for opticalengine assembly of claim 1, wherein the air duct device has a main body,and a partition for dividing the main body into a front air duct and arear air duct.
 5. The cooling apparatus for optical engine assembly ofclaim 4, wherein the front air duct has a diversion isolating board withtwo aslant surfaces, and is divided into a left and a right air ducts.6. The cooling apparatus for optical engine assembly of claim 5, whereinthe right air duct is isolated by an aslant isolating board, forming aninternal air duct leading to the imaging assembly and a second air ductleading to the external surface of one of the light valves.
 7. Thecooling apparatus for optical engine assembly of claim 5, wherein theleft air duct is isolated by an aslant isolating board, forming aninternal air duct and a third air duct leading to the external surfaceof one of the light valves.
 8. The cooling apparatus for optical engineassembly of claim 3, wherein the rear air duct has a downwardly aslantguiding surface at one end, and leads to the branch air duct at theother end.
 9. The cooling apparatus for optical engine assembly of claim4, wherein the rear air duct has a downwardly aslant guiding surface atone end, and leads to the branch air duct at the other end.
 10. Thecooling apparatus for optical engine assembly of claim 4, wherein therear air duct proximate one side of the main body forms a first air ducttowards the external surface of one of the light valves.